The present invention relates to control linkages and pertains particularly to a control linkage having a single pedal for coordinated control of throttle and transmission of a vehicle.
Many industrial vehicles, such as lift trucks and the like, require that the vehicle operator perform numerous functions, such as control of implements such as lift forks and the like of the vechicle, at the same time it is controlling forward and reverse and steering of the vehicle. It is, therefore, desirable that the number of control members that require manipulating be reduced as much as possible. Numerous arrangements for combining many of these functions in single controlled members have been proposed in the past.
When such industrial trucks employ hydrostatic transmissions wherein forward and reverse is accomplished by swiveling of the swash plate of the pump of the hydrostatic transmission in one or the other direction about a neutral position, the forward and reverse function of the vehicle can be incorporated in a control which simultaneously controls the engine throttle of the vehicle. One difficulty with incorporating this function; however, is that the forward and reverse of the vehicle must move in opposite directions whereas the control of the throttle linkage must move in a single direction.
Many linkages have been proposed for accomplishing this simultaneous control. However, while many of these are satisfactory in one or more respects they also have drawbacks. For example, many such systems are complicated and expensive to manufacture. Others, while fairly simple and inexpensive to manufacture, require complicated or awkward movement of the operator for accomplishing the necessary or specified controls.